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Quantum Hall Interferometry in Triangular Domains of Marginally Twisted Bilayer Graphene
Phanibhusan S Mahapatra1, Manjari Garg2, Bhaskar Ghawri1
1Department of Physics, Indian Institute of Science, Bangalore 560012, India.
Nano Letters
|July 7, 2022
Summary
Researchers developed a novel Quantum Hall interferometer using twisted bilayer graphene. This device enables phase-coherent interference of edge modes, crucial for studying fractional quantum Hall states and non-Abelian braiding statistics.
Area of Science:
- Condensed Matter Physics
- Quantum Information Science
Background:
- Quantum Hall (QH) interferometry is key for braiding statistics of fractional QH states.
- Observing fractional statistics demands phase coherence and suppressed Coulomb charging energy.
Purpose of the Study:
- To demonstrate a new type of QH interferometer.
- To explore interference effects in marginally twisted bilayer graphene (mtBLG).
Main Methods:
- Utilized a marginally twisted bilayer graphene (mtBLG) device with twist angle θ ≈ 0.16°.
- Operated the device in the Quantum Hall regime.
- Measured magneto-thermopower oscillations in the density-magnetic field phase space.
Main Results:
- Observed distinct electronic Fabry-Pérot and Aharonov-Bohm oscillations at Landau level filling factors ν = 4, 8.
- QH interference effects were intrinsic to triangular AB/BA domains in mtBLG.
- Demonstrated diminished Coulomb charging effects.
Conclusions:
- Phase-coherent interference of QH edge modes was achieved without complex gate architecture.
- The mtBLG interferometer is a promising platform for realizing non-Abelian braiding statistics.
- This work simplifies experimental approaches to fractional quantum Hall phenomena.
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